Once you have logged into the portal, you can access your profile by clicking on your name at the top right corner.
You will now see your profile page with the option to change your name, contact information, but also "Change username or password".
When you enter your new password, there will be a box indicating how secure the password is.
Remember to use both uppercase (A-Z) and lowercase (a-z) letters, numbers (0-9), and special characters (!"#$%&/@£$), and use at least 8 characters. No spaces are allowed.